WHAT IS IT?

As an extension of the simple economy model of Uri Wilensky (2011), This model has been developed to show and explain following issues:

1: How does the economic inequaliy emerge in an economic system?

2: How does sadaqah as an voulntary charity in Islam help reducing this emergent inequality?

3: As entities that receive sadagah from benefactors and allocate it to the needy, how can charity organizations affect the alleviation of the emergent economic inequality?

In this model, each human agent has a tendency towards giving one unit of money to another one (at a random manner), each agent does it until its money gets finished. According to statsitistical mechanics, the interaction of agents gradually widens the distance between five lower decils (bottom 50%) and higest decile (top 10%). When the total amount of top 10% becomes more than or equal to that of bottom 50%, this causes the economic system to go to a critical stage. In such a situation, if there are some charity organizations, they come to scene to help lower economic deciles and economic system to exit the critical stage. Thes entities have two different ways of financing as follows:

1: They have an independent money (in this simulation, one-fifth of total money of all agents)

2: They receive the Islamic charity (sadaqah) that some of agents give and allocate it to lower deciles.

When charities have the first way of resourcing, all of them can just take one of two following strategies for allocating resources among the needy agents:

1) When the system goes to a critical stage, they hlep the poorest agent ( by one unit of money) in each time step until the system exits the critical stage.
2) When the system goes to a critical stage, they hlep bottom 50% (by one unit of money for each one) in each time step until the system exits the critical stage.

When charities have the second way of resourcing, all of them can just take one of two following strategies for allocating resources among the needy agents

1) When the system goes to a critical stage, just the richest agnet gives sadaqah ( a unit of money) to the charity entity and it allocates it to the poorest agent
2) When the system goes to a critical stage, just c% of richest decile gives sadaqah (a unit of money by each agent) to the charity entity and it allocates it randomly to d% of the bottom 50%.
3) When the system goes to a critical stage, just k% of decile-10 (top 10%), p% of decile-9 and v% of dfecile-8 give sadaqah (a unit of money by eah person) to the charity entity and it allocates it as following:
sadaqah paid by k% of decile-10 is allocated to x% of decile-1
sadaqah paid by p% of decile-9 is allocated to y% of decile-2
sadaqah paid by v% of decile-8 is allocated to z% of decile-3

HOW TO USE IT

"setup Button" is for model setup.

"go button" is to run the model.

"sepcified-random-seed switch" is On when a seed can be specified for a specific experimentation and is Off when the system is randomly simulated in each run.

"specified-seed input" is to receive the seed when the sepcified-random-seed switch is On.

"num-of-people slider" is for determining the number of human agents before any run.

"money-amount slider" is for determining the money amount of human agents before any run.

"initial-eqaul-money switch" is On when all agents have the same amount of money in the begining and is Off when all agents dont have the same amount of money in the begining.

"critical-threshold slider" is for determining the critical point before any run (when the difference between total money of top 10% and that of bottom 50% becomes equal to more than this point, the economic system goes to a critical stage).

"num-of-charities slider" is for determining the number of charity entities before any run.

"sadaqah switch" is On when people of the socity tends to pay sadaqah in critical stage of econmoy and is off when no agent pays sadaqah in such a stage.

"tick-threshold input" is for determining the time of run stop.

"compute-class switch" is On for computing the classes otherwise off.This slider has been taken from wealth distribution model of uri Wilensky (1998) .

"compute-Lorenz-and-Gini switch" is On for computing Gini coefficient and Lorenz curve otherwise off.This slider has been taken from wealth distribution model of uri Wilensky (1998).

When people give sadaqah, allocation strategies and related parameters are as follows:

"allocation-strategy? chooser" includes:

s-one: when the system goes to a critical stage, just the richest agnet gives sadaqah (a unit of money) to the charity entity and it allocates it to the poorest agent.
s-two: when the system goes to a critical stage, just c% of richest decile gives sadaqah ( a unit of money by each agent ) to the charity entity and it allocates it randomly to d% of the bottom 50%.
s-three: when the system goes to a critical stage, just k% of decile-10 (top 10%), p% of decile-9 and v% of dfecile-8 give sadaqah (a unit of money by eah person) to the charity entity that allocates it as following:
sadaqah paid by k% of decile-10 is allocated to x% of decile-1
sadaqah paid by p% of decile-9 is allocated to y% of decile-2
sadaqah paid by v% of decile-8 is allocated to z% of decile-3

"percentage-of-decile-10 slider" is for determining the number of members of decile-10 participating in paying sadaqah to charity entities.

"percentage-of-decile-9 slider" is for determining the number of members of decile-9 participating in paying sadaqah to charity entities.

"percentage-of-decile-8 slider" is for determining the number of members of decile-8 participating in paying sadaqah to charity entities.

"percentage-of-decile-1 slider" is for determining the number of members of decile-1 receiving the sadaqah from charity entities.

"percentage-of-decile-2 slider" is for determining the number of members of decile-2 receiving the sadaqah from charity entities.

"percentage-of-decile-3 slider" is for determining the number of members of decile-3 receiving the sadaqah from charity entities.

"percentage-of-five-lower-deciles slider" is for determining the number of members of five-lower-deciles receiving the sadaqah from charity entities.

When people dont give sadaqah, allocation strategies and related parameters are as follows:

"allocation-strategy? chooser" includes:

ws-one: When the system goes to a critical stage, charities hlep the poorest agent (by one unit of money) in each time step until the system exits the critical stage.
ws-one: When the system goes to a critical stage, charities hlep bottom 50% (by one unit of money for each one) in each time step until the system exits the critical stage.

THINGS TO NOTICE

Gini coefficient and Lorenz curve are technically used for distribution of wealth or income. This model deals with distribution of money so It is unnecessary to use these switches for simulation.In addition, they can majorly slow the operation of model runs when lots af human agents and high amount of money are used in simulations.

EXTENDING THE MODEL

Some new agents and beghavioral rules can be added to make this model more realistic some of which are as following:

1- Human agents can directly give and receive sadaqah

2- Other phenomena such as distribution of wealth and income can be simulated

3- other economic reule of Islam such as Zakat and so on can be added to the model

4- Some features such as educational level and tendency to entrepreneurship can be added to agents to enable them to interact productively.

5- Some new agents such as venture capital funds, banks and so on can be added to the model to make the economic system more interactive. One instance for this can be venture capital funds set a priority for entrepreneurial eduacted agents living in poor deciles of the society.

RELATED MODELS

Simple Economy

Wealth Distribution.

CREDITS AND REFERENCES

The author and domain experts who participated in developing this model can be contacted by following emails: